Apparatus for grinding and polishing precious stones.



B. LOESSER.

APPARATUS FOR GRINDING AND POLISHING- IBUIOUS STONES.

APPLICATION FILED FEB. 14, is

Patented A1012 28, 19M.

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Wane/000s Q. 7," 1 5 A E. LOESSER. APPARATUS FOR GRINDING AND POLISHING PRECIOUS STONES.

APPTJICUKIIOLT FILED PBB.14,1913. 1 69141 91 Patented Apr 28, 1914.

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UNITE smarts Parser rrion.

ERNEST LOESSER, OF GLEN RIDGE, NEW JERSEY, ASSIGNGR, BY DIRECT AND MESH'E ASSIGNMENTS, TO NEW DIAMONE EGLISHING TOOL COMPANY OF AMERICA, INC., OF NEW YORK, N. 5. ACORPORATION OF NEW YGBK.

APPARATUS FOR GRINDING AND POLISHING PRECIOUS STONES.

Specification of Letters Patent.

IPatented Apr. as, iota.

Application filed February 14, 1913. Serial No. 748,325.

- Grinding and Polishing Precious Stones, of

which the following is a specification.

In apparatus constructed in accordance with this invention there is a dop holder adapted to be. carried in an ordinary hand stock or tongue that stands upon 'the table of the machine when. the stone is being ground upon the'lap. This dop holder, has a dop receptacle open at top and bottom and interiorly a seat adapted to receive a dop in the end of which the stone to be 53* set, and at its head a circle of repreference, the dop receptacle has conical seat and the dop is of corresponding s so .1-.) tit accurately and be rotatable on The recesses afford ameans of t-ment by rotation and the angle holder, and consecl seat.

quently lop, is also madead ustab e dop is formed, by a molci op. if metal of suitable composition in t end of which the stone to be polishe set by the castingoperat-ion and the upper end or head of the dop produced by the some casting operation is formed with a projecting circular flange in which at one operation, byineans of a suitable cutting tool, equally spaced recesses are out.

In the accompanying drawings, which show this invention in a form which experience has demonstrated it to be practical and eflicient,Figure l. is aside elevation:

Fig. 2, a plan view Fig. 3, a vertical section on an enlarged scale: Fig. 4:, a side elevation: Fig. 5, a plan view showing the dop holder opened to receive a dop: Fig. 6, a side elevation of a dop with a stone in the apex end: and Fig. 7, a plan viewof the 1 indicates a portion of-thetable of a diamond polishing machine and 2, the ordinary lap.

3 is the removable stock or tongue at the outer end of which are twoposts 4, that rest upon the table and a horizontally project ing rod 5 that isheld against lateral dis placement by a pin 6 extending up vertically from the table. Adjacent the lap there is another. pin 7 fixed vertically in the table and serving to support the frame against displacement in opposite direction. v

'Also, adjacent the lap there is a post having an adjustable screw head 9 that forms a stop which, as is generally understood, limits the descent of the inner end of the frame 3 and so limits the grinding action of the lap upon a stone. The part of the frame overlying the lap is formed-with a head 10 having a vertical bore in which is secured, in the manner shown or otherwise, a spindle 11. This spindle is circumferentially adjustable and its axis is vertical to the horizontal plane in which the polishing face of the lap rotates. On the lower end of the spindle is an arc piece 12 having formed in its under face an arc-shaped dove-tail way 13 and on one of its side edges an appropr ate scale'l i.

The dop holder is carried adjustably upon the arc member 12, 13. The dop holder comprises a curved portion 15 that is circumferentially formed with a dove-tail way 16 corresponding to and fitting upon the dove-tail way 13 upon which it is adjustable and upon which it may be rigidly fixed when adjusted. The manner of setting or looking the. arc-shaped member 15 of the dop holder upon the spindle head 12,.13 may assume a variety of forms; In the presentiiinstance the locking means is in the form of a bolt 17 that occupies a bore formed in a. circular boss 18 and in the under-cut sides of the way of the member 15. Intermediate its ends the bolt is cut away so as to be flush with the curved face ofthe floor 20 of the dove-tailway in the dop holding member 15. To one end of the bolt is applied a nut 21 and the shoul-v der at the other end is cut away to fit the under-cut side 22 of the rib forming the way 13 of the part 12. When the nut is screwed up there is an accompanying endwise movement of the bolt that results in. clamping the member 15 firmly in any posi tion in which it may may he set. The other memberor half 23 of the dop holder is hinged: to one end of the part idler hinge-pin 24:. I The outer portion of part 23 is formed with a conical clop seat or receptacle 25 in which fits the correspondingly shaped dop 26, the apex end of which projects beyond the seat and has secured therein a gem 27. The head of the dop has cast with it an annular flange 28 and above it a table 29. By the aid of an apprdpriate cutting tool equally spaced recesses 30 x nay be cut in the flange. The number of such recesses will,.of course, depend on the series of facets to be produced upon the stone. In the case of diamonds an appropriate number of recesses is thirty-two. in the sides of the dop at the apex end are reand hold it accurately in the dop seat. The

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dop holder 15, 23, is held firmly closed by a screw bolt 34 passing freely through any aperture 35 in an enlargement 36 at one side of the part 23 and screwing into a threaded co-incident aperture in an enlargemerit 37 on the part 15. The dop is thus held firmly although susceptible, under suitable stress, of partial rotation in the holder. I j

It will be seen from T igs. 3 and d that the axis of the (lop is forty-five degrees from the vertical axis 0f-spindle 11. The stone is located at the angle or point. of intersection of such two axes and such point is the center of the arc in which the dop holder is adjustable upon the head of the spindle 11. in all ad ustments the stone is there held at the center of such are of adjustment, 2'. it is always intersected by the axis of the spindle. The recesses .30 constitute means by'which different regulated or determined increments of rotation may be given to the dop to meet the requirements respecting the facets to be formed upon the gem. A means for freeing the dop for such rotation and then positively looking it is highly desirable if not essential and such means may be as follows. Hinged upon the face of the'pa-rt 23 to the rear or inside of the dop seat is a lever 38 and also upon the same axis a locking pawl 39. A plate or wire spring 40 is attached to the pawl and at the other end is held in a recess aim the face of a projection 42 on the member The detent pawl is formed with a nose 43 adapted to engage the recesses 30. The lever 38 extends beyond the end of the pawl into operative engagement with a plunger aphasia of the lever 38. Between the head and the bushing a coiled reaction spring 4:8 surrounds the spindle and on the latter, outside of or beyond the bushing, is a transverse pin 4-9. When the spindle is rotated by means of the pin 49 the-latter rides up on the cam way 46 and the conical head of the spindle is withdrawn permitting the spring to lift the pawl 39 and with it thelever' 38 thereby withdrawing the pawl from one of there cesses in the head of the dop. JVhen, however the pin 49 passes the high point of the cam, spring 48'moves the headed spindle inwardly and forcesthe lever and with it the pawl toward the dop to positively engage a recess therein. v

On the upper member 15 there is an index point 50 that cotiperates with the scale it on the arcuate head 12 of the spindle 11 which latter is rotatably adjustable. This allmds a guide for accurate adjustment of the dop with respect to presentation of the gem to the lap in the required or advantageous relation thereto. Surrounding the ole of thedop, there is a separate ring 51 shown as a split ring frictionally embracing the table. On this ring there is an arrangement of numbers or other indicia respectively disposed opposite recesses in the flange of the dop head. lln the present instancefthcse in-- dicia are shown as a series of numbers. On the side of the part 23 of the dop holder there is an index point 52 which stands im mediately opposite a recess 30. This atl 'ords a means for accurately. determining the position of the stone with respect to the initial and subsequent cuts of the lap.

Different stones require different handling to produce the best results because stones vary in grain and shape. The various adjustments above referred to enable an expert to determine the setting of the stone in the dop and thereafter examine itand adjust the dop in theholder and the latter to the lap in such way that the first and therefore the succeeding consecutive cuts will be made to the best advantage for any particular stone.

On the face of the table 29 of the (lop there is placed an identifying number or a series of numbers or a particular relation of num bers or other characters that serve to indi- ,cate the particular lot'of stones from which that in the dop has been taken. The drawings show this identifying character as 1I1(l1 cated in an arbitrary way by the letter A. This identifying mark may be conveniently impressed into the face of the table of the dop by means of a suitable die.

In diamond grinding and polishing apparatus means of supporting that part of the stone projecting beyond the dop have been employed. Such adevice is shown in the drawing. It comprises a rod 53 having a gem supporting foot at right angles thereto. This foot is flattened and may be bifurcated at the end to form a claw 54 that embraces the sides of the stone. It may, however, be flat and engage the bottom of the stone. Both forms are well known. The rod 53 is seated in a bore in the dop holder part 23 in rear of the dop seat and parallel with the axis thereof and the rod is secured in ad usted position or released to disengage the claw from the stone by means of a clamp rod 55 seated in a transverse bore in the part 23 and having a clamp nut 56 upon its threaded projecting end. This rod is formed with a circular transverse recess 57in which rod 53 lies. When nut 56 is loosened, the rod 53 is loose in its socket and may be adjusted or withdrawn. When, however, the nut is tightened up, endwise stress on rod 55 clamps the rod 58 in position.

I claim:

1. Diamond grinding and polishing apparatus comprising a dop holder, a dop therein rotatably adjustable and whose axis is at an angle to a vertical line and means for adjusting the holder in an arc of which the stone iii the dop is the center or substantially so.

2. Diamond grinding and polishing apparatus comprising a dop holder, a dop therein rotatably adjustable and whose axis is at an angle to a vertical line, means for adjusting the holder in an arc of which the stone in the dop is the center or substantially so and means for adjusting the holder about a vertical axis that passes through the stone in the dop.

8. Diamond grinding and polishing apparatus comprising a dop holder, a dop therein rotatably adjustable and whose axis is at an angle to a vertical line and means for adjusting the holder in a vertical plane ii an arc of which the stone in the dop is the center or substantially so.

LDiamond grinding and polishing apparatus comprising a dop holder having a conical seat open at both ends and the axis of which is at an angle to a vertical line, a conical dop seated in such seat and projectingtherefrom at its apex end, a circular series of recesses in the head of the dop, lockin and releasing. means cooperating with sai recesses and means for adjusting the dop holder and dop in an arc of which the cem ter is the pointot intersection of lines-coin oident with the conical sides of the dop.

5. Diamond grinding and polishing apparatus comprising the combination of a vertical rotatably adjustable spindle, an are shaped way carried at the lower end thereof, a dop holder the axis of which is disposed at an angle that intersects the axis of the spindle which point of intersection is the center of the arc-shaped guide way or sub stantially so.

6. Diamond grinding and polishing apparatus comprising the combination of a vertical rotatably adjustable spindle, an areshaped way carried at the lower end thereof, a dop holder having a conical or tapered dop seat the axis of which is disposed at an angle that intersects the axis of the spindle which point of intersection is the center of the arc-shaped guide way or substantially so.

'Z. Diamond grinding and polishing apparatus comprising the combination of a vertical rotatably adjustable spindle, an arcshaped way carried at the lower end thereof, a dop holder having a conical or tapered dop seat the axis of which is disposed at an angle that intersects the axis of the spindle which point of intersection is the center of the arc-shaped guide way or substantially so, a dop haying a corresponding tapered formation to fit said seat and means whereby the dpp may be rotatably adjusted in the seat.

8. Diamond grinding and polishing apparatus comprising a rotatably adjustable dop in the apex end of which the stone is placed a separate ring held at the head of the dop and having thereon characters atfording indications of the manner in which the dop is to be rotatably adjusted, a dop holder in which said dop is seated whose axis is at an angle to a vertical line and whicl'i is provided with means for locking and n l ing the dop for adjustment and me? adjusting the holder in a vertical plan arc.

9. Diamond grinding and polishing apparatus comprising a rotatably adjustable dop in the apex end of which the stone is the point of intersection of said axis and the axis of the dop. 10. Diamond grinding and polishing apparatus comprising a dop holder having a .main body part and a part hinged thereto, ,the hrngedpart having in it a dop seat l whose axis is dlsposed at an angle to a ver- 1'30" ticel line, means whereby when the two parts are closed one against-the other the dop'is held in said seat, said ln ain'body part being formed with an arc-shaped Way, and 5 a dop holder support having a, correspohdin arc-shaped Way upon which the main lolly part of the holder is adjustable.

In testimony whereof, I have hereunto subscribed my name.

' ERNEST LUESSER. Witnesses i M. L. SMITH, H. DE MQYA, 

